[jolsa-perf:bpf/tracing_multi_4 33/34] kernel/trace/ftrace.c:5266:1: warning: no previous prototype for 'ftrace_find_direct_func_list'

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git bpf/tracing_multi_4
head:   1637b6b5bec11596e52cdc0a6eadfa45a15276c3
commit: f593767b216bc743e441c394e560546dcaaacc05 [33/34] ftrace: Factor list functions for ftrace_direct_func find and alloc
config: s390-randconfig-r044-20220728 (https://download.01.org/0day-ci/archive/20220728/202207281208.EogzobID-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git/commit/?id=f593767b216bc743e441c394e560546dcaaacc05
        git remote add jolsa-perf https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
        git fetch --no-tags jolsa-perf bpf/tracing_multi_4
        git checkout f593767b216bc743e441c394e560546dcaaacc05
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash kernel/trace/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   kernel/trace/ftrace.c:295:5: warning: no previous prototype for '__register_ftrace_function' [-Wmissing-prototypes]
     295 | int __register_ftrace_function(struct ftrace_ops *ops)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/ftrace.c:338:5: warning: no previous prototype for '__unregister_ftrace_function' [-Wmissing-prototypes]
     338 | int __unregister_ftrace_function(struct ftrace_ops *ops)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/ftrace.c:4051:15: warning: no previous prototype for 'arch_ftrace_match_adjust' [-Wmissing-prototypes]
    4051 | char * __weak arch_ftrace_match_adjust(char *str, const char *search)
         |               ^~~~~~~~~~~~~~~~~~~~~~~~
>> kernel/trace/ftrace.c:5266:1: warning: no previous prototype for 'ftrace_find_direct_func_list' [-Wmissing-prototypes]
    5266 | ftrace_find_direct_func_list(struct ftrace_direct_list *list, unsigned long addr)
         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/ftrace_find_direct_func_list +5266 kernel/trace/ftrace.c

  5251	
  5252	/**
  5253	 * ftrace_find_direct_func - test an address if it is a registered direct caller
  5254	 * @addr: The address of a registered direct caller
  5255	 *
  5256	 * This searches to see if a ftrace direct caller has been registered
  5257	 * at a specific address, and if so, it returns a descriptor for it.
  5258	 *
  5259	 * This can be used by architecture code to see if an address is
  5260	 * a direct caller (trampoline) attached to a fentry/mcount location.
  5261	 * This is useful for the function_graph tracer, as it may need to
  5262	 * do adjustments if it traced a location that also has a direct
  5263	 * trampoline attached to it.
  5264	 */
  5265	struct ftrace_direct_func *
> 5266	ftrace_find_direct_func_list(struct ftrace_direct_list *list, unsigned long addr)
  5267	{
  5268		struct ftrace_direct_func *entry;
  5269		bool found = false;
  5270	
  5271		/* May be called by fgraph trampoline (protected by rcu tasks) */
  5272		list_for_each_entry_rcu(entry, &list->funcs, next) {
  5273			if (entry->addr == addr) {
  5274				found = true;
  5275				break;
  5276			}
  5277		}
  5278		if (found)
  5279			return entry;
  5280	
  5281		return NULL;
  5282	}
  5283	

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